The invention relates to a method of making foam and more particularly, to a method of making rigid foam produced from components contained in a single container.
Uses of foams include protection of sensitive components, such as electronics, formation of structures, insulation, and in security applications. Rigid structural foams have been developed for some applications but have been based upon two component, reacting systems such as polyurethanes that require complex hardware designs and high maintenance (I. O. Salyer, J. L. Schwendenian, and C. E. McClung, J. Cellular Plastics, 1968, 4(9)). Polyurethane foams also have a significant set-up time for the requirements of some applications.
Smits (U.S. Pat. No. 5,391,317, issued on Feb. 21, 1995) sought to manufacture foam having both good dimensional stability and thermal insulation using hydrocarbons as blowing agents. This reference taught the use of a particular mixture of C5-6 alicyclic alkanes, isopentane and n-pentane blowing agents in particular molar percents, in combination with a polyol mixture made up of an aromatic initiated polyether polyol, an aromatic polyester polyol, and a different amine-initiated polyether polyol. As the aromatic-initiated polyether polyol, Smits suggested using an alkylene oxide adduct of a phenolformaldehyde resin. The particular mixture of alicyclic and isomeric aliphatic alkane blowing agents is taught by Smits as producing foam having good thermal insulation values.
Wilson et al. (U.S. Pat. No. 6,245,826, issued on Jun. 12, 2001) describe a polyisocyanate based rigid closed cell foam, prepared by reacting an organic isocyanate with a polyol composition in the presence of a blowing agent, with good thermal insulation properties and dimensional stabilities.
Zerafati et al. (U.S. Pat. No. 6,225,365, issued on May 1, 2001) describe a polyvinyl chloride (“PVC”) foam prepared with physical blowing agents, more particularly to PVC foam blown with one or more gaseous hydrofluorocarbons (“HFC”s) such as 1,1,1,2-tetrafluoroethane.
Mercando et al. (U.S. Pat. No. 6,114,403, issued on Sep. 5, 2000) describe rigid polyurethane foam by reacting an organic polyisocyanate and a polyol in the presence of a blowing agent, a cell stabilizer and a catalyst composition.